Qingyuan steel manufacture process (a)

　　Steel processing production process (a):
(1) Qingyuan Steel Mechanical Index: mechanical indicators, including structural steel yield point, tensile strength, elongation, low temperature impact toughness. These indicators should be consistent with "Steel design specifications" requirement, but only when the low temperature impact toughness structural work may be in a low temperature environment to test. Determination of steel mechanical index shall comply with the "Steel mechanical and process performance test sampling provisions"
(2) steel chemical composition: steel and processability, toughness, durability, and so on. Mainly the carbon content, content and content restrictions sulfur, phosphorus and other impurities alloying elements are to comply with (GB222-84) requirements.
(3) process performance: process performance include weldability and processing properties. Weldability carbon content or carbon equivalent (low-alloy steel) related to available solderability test evaluation. Processing performance is determined by the cold bend test. Press (GB232-88) as standard.
(4) geometry deviation: Deviation dimensions and theoretical size steel (steel, steel, bar, pipe) must be within the allowable range. Tolerance values ​​can refer to the national standard GB709-88, GB706-88, GB787-88, GB978-88, GB707-88, GB816-87 like.
(5) steel contour deficiencies: the steel surface may not have bubbles, scarring, crack, crack, fold, iron oxide inclusions and pressed into the skin. These defects must be removed, where the depth of the recess is greater than the thickness of steel can not be cleared after a negative deviation. In addition, when the steel surface rust, pitting or scratches and other defects, the depth shall not exceed 1/2 of the thickness of steel negative bias values.
(6) Mechanical cutting: Using mechanical forces (shearing, sawing, grinding) cutting, the corresponding mechanical shears, saws, grinders and other, more suitable for the thickness of 12 ~ 16mm or less linear or steel profiles cutting.
                                         Shears
(7) Gas cutting: using oxygen - acetylene, propane, liquefied petroleum gas flame heating to melt the metal and use compressed air to remove the ablation of the molten metal, so that the metal cut off, suitable for curve cutting and cutting long.
(8) Plasma cutting: using a plasma arc cutting stream implementation, suitable for cutting stainless steel and other refractory materials.
(9) Heat forming: refers to steel heated to a temperature before processing. This method is suitable for forming, bending and correction at room temperature can not do the work. Thermal processing termination temperature not lower than 700 ℃. The heating temperature generated blue brittle at 200 ~ 300 ℃ when the steel, non-hammering and bending. Carbon content exceeds the range of low carbon steel in general can not be hot-working.
(10) Cold forming: it is carried out at room temperature. The permanent deformation due to external forces beyond the material yield strength of the material will produce the desired, or due to an external force exceeds the ultimate strength of the material leaving certain parts of the material required and material detachment. Cold hard and brittle the material has a tendency, which can make the steel by heat treatment to restore a normal state or hardening plane cut off more serious edge portion. Carbon steel can not be cold when the ambient temperature is below -16 ℃. Below -12 ℃, low-alloy steel can not be processed.